Currently, energy generation systems are seeing an increased use of renewable energy sources, such as solar energy. For example, solar energy collection may occur by use of photovoltaics. In order to attain grid-parity for solar photovoltaic (PV) systems in terms of cost, the United States Department of Energy (DOE), for example, has estimated that power conversion equipment, such as a PV inverter, which converters direct current (DC) energy into grid compatible alternating current (AC) energy, should not cost more than $0.10/Watt. The $0.10/W budget for the inverter is all inclusive of the cost of the hardware, installation and operation & maintenance (O&M) over its lifetime. An assessment of the existing PV inverter topologies that are in existence and those that are projected for future developments indicates a striking difference between present and projected cost and the DOE target costs for grid parity. Worldwide, the average selling price of a PV inverter (averaged over all markets and kW sizes) in 2010 was $0.29/W, excluding installation and O&M costs.
Centralized inverters (typically 100 kW and above in size) that aggregate the functionality of DC-to-AC conversion at a single point costs about two to three times less than microinverters or microconverters. However, traditional centralized inverters are not able to capture energy that is lost due to panel to panel variation. Studies have indicated that the uncaptured energy is not only a revenue loss, but may also contribute to a faster rate of PV panel degradation over time, due to higher cell operating temperatures. While microinverters and microconverters cost significantly more than centralized inverters, they have the potential to increase system performance by significantly improving the granularity of the maximum power point tracking functionality since they are, typically designed to interface to only one single PV panel. Despite their perceived performance enhancement capabilities, present microinverter or microconverter solutions are priced significantly outside of the DOE's grid-parity targets.
Therefore, despite recent resurgence of activity in the PV inverter technology space with a plethora of a new topologies and architectures being proposed, a need exists for a solution that is able to achieve significant cost reductions while being able to retain the perceived benefits of microinversion or microconversion. A further need exists for energy efficient solar energy collection without compromising the power conversion efficiency. Systems and methods disclosed herein meet these needs and are able to derive further benefits from the proposed architecture which, cumulatively, result in additional system cost reduction for the overall solution.